package com.zto.sch.base.normal;

import java.util.HashMap;

/**
 * @program: sch-diy-parent
 * @description:
 * @author: sch
 * @create: 2021-01-08 14:01
 **/
public class HashMapDemo {
    public static void main(String[] args) {
        HashMap<String, String> hashMap = new HashMap();
        hashMap.put("key1", "value1");
        hashMap.put("key2", "value2");
        hashMap.put(null, "value2");
        hashMap.put(null, null);

        String value1 = hashMap.get("key1");
        System.out.println(hashMap);
        System.out.println("value1:" + value1);

    }
}
